Dome errors

[Paul Luckas]

Bob,

I'm getting intermittent errors which I think are shutter erorrs, in ACP on first connection. It's as if the dome driver does not know what state my shutters are in. I can sometimes jag the correct start up procedure by opening and closing the dome using another application - which somehow seems to 'initiatlise' the shutters so that when I start the telescope in ACP the correct shutter status is indicated.

I presume this is a driver issue - and a call to Diffraction Ltd may be in order (MaxDome II) ?

Paul

[Rob Hawley]

I also have a MaxDome and was initially plagued with dome errors. I ditched my USB-serial converters and instead install a PCI serial card. I have not had any problems with the dome since I did that.

The other thing to check is your shutter antenna. I initially just used a loop of wire like in the Max Dome documentation. That proved to not be reliable. I replaced the loop with two loops of wire each circling the entire dome. You can monitor for poor signal by looking at the lights in the shutter controller.

I debugged this all pre ACP so I know this was purely hardware.

[Paul Luckas]

Thanks Rob.

Paul

[Bob Denny]

I'm with Rob. If you think about it, there really isn't a way that ACP could cause this.

[Paul Luckas]

It's looking increasingly like a sick RS232 port on one of my dual serial port PCI-E cards. They are brand new, along with the PC, so I guess if there are going to be problems it will be during the early days.

I've been testing on a 'good' port, and things are behaving.

Thanks for the reminder that hardware can fail.

Paul

[Bob Denny]

Look at the power supply voltages too. Under load. Low voltage means low signal margins.

[Rob Hawley]

Ah yes I forgot about that change

My dome manufacturer suggested that I get a 35A power supply (Pyramid PS36KX 35-Ampere Power Supply with Built-In Cool Fan). I don't know if there was a case where the smaller supply caused faults visible by the computer software, but the larger supply is able to take the high loads of the DC motor starting. The smaller supply caused the dome to occasionally stall for a moment while turning.